Did you know that Paul Revere rode through the countryside calling men to arms class?

where does the comma belong?
how can i rewrite this sentence with a comma?

To rewrite this sentence with a comma, you would have to make it 2 different sentences. So you would say: Did you know that Paul Revere rode through the country side? He was calling men to arms class.

So you would combine them again and put the comma after the last word in the first sentence making it: Did you know that paul Revere rode through the countryside, calling men to arms class?